Hypogonadism, MalePhase 3NCT06689085
52 Week Study + 24-Month Long-Term Extension of Safety, PK, & Efficacy of XYOSTED® for Testosterone Replacement in Male Adolescents With Hypogonadism
A Phase 3 study testing Testosterone enanthate in people with Hypogonadism, Male, run by Halozyme Therapeutics at 22 sites in United States.
Trial summary
This is a 52-week open label single arm study + 24-Month long-term safety extension to investigate the effects of XYOSTED, as testosterone replacement therapy, on adolescent males with either primary or secondary hypogonadism. Read more about this study
- Who is it for?
- Ages 12 to 17 years, men only
- Conditions the study is for
- Hypogonadism, Male
- What is being tested?
- Testosterone enanthate
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 100 participants
- Where
- 22 sitesUnited States
- Study dates
- 7 Mar 2025to Mar 2030
- Phase
- Phase 3
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 12 to 17 years
- Men only
- No healthy volunteers
- Child
Who may be able to join
- Diagnosed with a deficiency or absence of endogenous testosterone due to primary or secondary hypogonadism of a known etiology. Children with combined hormone deficiencies are permitted to enroll (but the child must already be receiving treatment for concomitant hormonal deficiencies)
- Participants receiving prior testosterone treatment must be receiving a stable dose for at least 12 weeks prior to Screening. Treatment naive participants are permitted to enroll.
- Have parent(s) or a legal guardian who will voluntarily provide written informed consent for the child to participate in the study
- Willing to provide assent for participation in the study
- Be a male 12 to < 18 years of age at the time of consent/assent
- Have Legally Authorized Representative who is able to understand and comply with all study procedures and agrees to have the child participate in the study program as outlined in the protocol
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- Requires chronic pharmacologic support for the initiation and/or continuation of pubertal maturation
- Have a body mass index (BMI)-for-age greater than the 5th percentile and weigh ≥ 30 kg.
- If sexually active with a female partner of child-bearing potential, agrees to:
- Practice true abstinence including 30 days after the last IP administration, or,
- Use 2 adequate forms of highly effective contraception, one of which should be a physical barrier, during the study and for 30 days after the last IP administration.
Who cannot join
- Has abnormal thyroid function tests at Screening. May supplement per usual clinical practice and rescreen up to two times.
- Has suspected or known constitutional growth delay in growth and puberty (CDGP)
- Has evidence of possible nutritional or gastrointestinal disorder that may impact growth (e.g., abrupt weight loss within the 3 months prior to Screening, unmanaged celiac disease, inflammatory bowel disease)
- Has a known allergy or hypersensitivity to XYOSTED, or to any of its ingredients (testosterone enanthate and sesame oil)
- Participants receiving prior treatment with testosterone who are not on a stable dose for at least 12 weeks prior to Screening.
- Has an allergy to foods or products containing sesame seeds or sesame oil
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- Has Stage 1 hypertension, defined as the average of 2 or more seated right arm BP measurements exceeding the 95th percentile for age, sex, and height, or SBP ≥ 130 mm Hg and/or DBP ≥ 80 mm Hg at Screening or Day 1.
- Has a clinically significant abnormal clinical laboratory test value at Screening, as determined by the Investigator including hematocrit > 48%, or >50% for patients living at high altitude if not receiving testosterone treatment, or hematocrit > 52% if already receiving testosterone treatment.
- Has a history of deep venous thrombosis or pulmonary embolism
- Has evidence of a clinically significant 12-lead electrocardiogram (ECG) abnormality at Screening, as determined by the Investigator
- Has a current suspected or diagnosed (and unresected) tumor of the pituitary gland with the exception of Rathke's cleft cyst or a stable non-functioning pituitary microadenoma (ie, lesion size < 10 mm that has not increased in size over a period of 1 year on repeat imaging), as determined by the Investigator
- Has an active malignancy or has received treatment for a malignancy within the 12 months before Screening
- Is currently receiving antipsychotic medication for any reason or is currently receiving selective serotonin reuptake inhibitor (SSRI) medication for depression
- Is receiving any other medication or has a condition that would preclude safe participation in the study or confound the evaluation of safety, as determined by the Investigator
- Has a history of suicidal behavior (i.e., actions intended to harm oneself), suicidal ideation (i.e., thoughts and plans about suicide), or suicide attempts
- Has any affirmative responses on the Columbia Suicide Severity Rating Scale (C-SSRS) questionnaire to questions #3, #4, or #5 or any affirmative response to questions #1 or #2 within the past 12 months on the suicide ideation questions (first section) OR any affirmative response on the suicidal behavior questions (the second section).
- Is currently taking supraphysiologic doses of systemic glucocorticoids for more than 3 weeks, except for intermittent short courses of exogenous glucocorticoids as needed for the treatment of asthma
- Has received any other investigational compound within 1 month prior to screening or 5 half-lives of the investigational product (whichever is longer)
- Has received gonadotropin-releasing hormone (GnRH) agonists, aromatase inhibitors, androgens (eg, dehydroepiandrosterone [DHEA]), anabolic steroids such as oxandrolone, or other sex steroids within 12 months before the Screening visit, or would require these treatments at any time during the study.
- Receiving cytochrome P450 (CYP) 3A4 or P glycoprotein (P-gp) inhibitors/inducers or medications that are metabolized by CYP3A4 or P-gp within 30 days of enrolment.
- Has a history of alcohol or drug abuse
- Has a history or clinical manifestations of significant renal, hepatic, cardiovascular, metabolic, neurologic, psychiatric, or other conditions that would preclude participation in the study, as determined by the Investigator
- Has chronic urticaria or dermatographism
- Has 25-hydroxy-vitamin D blood level < 20 ng/mL. Participants with initial vitamin D blood measurement < 20 ng/mL may enroll while they receive supplementation per clinical practice
Trial locations and contacts
22 sites in 1 country. Contact the study team or a site near you to ask about taking part.
22 sites in 1 country
United States22 sites, 22 recruiting
- Recruiting
Children's Hospital Colorado
Aurora, Colorado, 80045
- Recruiting
Boston Children's Hospital
Boston, Massachusetts, 02115
- Recruiting
University of Virginia School of Medicine
Charlottesville, Virginia, 22908
- Recruiting
Ann & Robert H. Lurie Children's Hospital of Chicago
Chicago, Illinois, 60611
- Recruiting
Prisma Health Children's Hospital - Midlands
Columbia, South Carolina, 29203
- Recruiting
MedResearch
El Paso, Texas, 79902
- Recruiting
Texas Children's Hospital
Houston, Texas, 77030
- Recruiting
Nemours Children's Specialty Care - Jacksonville
Jacksonville, Florida, 32207
- Recruiting
The DOCS
Las Vegas, Nevada, 89113
- Recruiting
Children's Hospital Los Angeles
Los Angeles, California, 90027
- Recruiting
Cedars-Sinai Medical Center
Los Angeles, California, 90048
- Recruiting
M Health Fairview U Minnesota
Minneapolis, Minnesota, 55454
- Recruiting
OUHSC Pediatric Diabetes & Endocrinology
Oklahoma City, Oklahoma, 73104
- Recruiting
Children's Hospital of Philadelphia
Philadelphia, Pennsylvania, 19104
- Recruiting
Primary Children's Hospital
Salt Lake City, Utah, 84112
- Recruiting
Rady Children's Hospital - San Diego
San Diego, California, 92123
- Recruiting
University of California San Francisco
San Francisco, California, 94143
- Recruiting
Seattle Children's Hospital
Seattle, Washington, 98105
- Recruiting
Washington University School of Medicine in St. Louis
St Louis, Missouri, 63110
- Recruiting
MultiCare Institute for Research & Innovation
Tacoma, Washington, 98405
- Recruiting
Children's Hospital at Montefiore
The Bronx, New York, 10467
- Recruiting
University of Massachusetts Memorial Medical Center
Worcester, Massachusetts, 01655
About this study
Official title: Open-Label, Multiple-Dose, 52-Week Study + 24-Month Long-Term Safety Extension to Evaluate the Safety, PK, & Efficacy of XYOSTED® for Testosterone Replacement in Male Adolescents With Deficiency or Absence of Endogenous Testosterone Due to Primary or Secondary Hypogonadism
This is a 52-week open label single arm study + 24-Month long-term safety extension to investigate the effects of XYOSTED, as testosterone replacement therapy, on adolescent males with either primary or secondary hypogonadism.
The study aims to determine the effectiveness of XYOSTED measured by continuation or induction of puberty in addition to XYOSTED dosage, safety and testosterone levels.
Read the detailed description
This is a Phase 3/4, open-label, multicenter study in approximately 100 males 12 to < 18 years of age with primary or secondary hypogonadism (congenital or acquired). Each participant will be screened for eligibility within 28 days before receiving his first dose of study drug on Day 1. During the Screening period, each participant will have a full clinical examination with pubertal staging, including 2 separate serum total testosterone (TT) measurements obtained in the early morning, where the average (Cavg) will be considered baseline value. Each participant will be categorized as having primary or secondary hypogonadism prior to dosing on Day 1.
Participants meeting all eligibility criteria will be assigned to a starting dose of XYOSTED based on their weight and Targeted Tanner Stage on Day 1. The Targeted Tanner Stage will be determined during Screening by an experienced pediatric endocrinologist.
Participants will have dose adjustments during the study to achieve their Targeted Tanner Stage. Dose adjustments will be based on reviewing the TT concentration between doses (Cmid) by measuring serum TT 14 days after the administration of XYOSTED for participants receiving the Q4W schedule, 7 days after the administration of XYOSTED for participants who are on the Q2W schedule, and 4 days after administration of XYOSTED for participants on the Q1W schedule. Participants will be evaluated for further dose adjustments approximately every 3 months to achieve the desired targeted TT level.
Following the 52-week primary study, participants may join a 24-month long-term safety extension study to continue the evaluation of XYOSTED in this population. Participants will return to the clinic at 6-month intervals for evaluation for clinical evaluations, and laboratory and pharmacokinetic assessments.
- Conditions
- Hypogonadism, Male
- Being tested
- Testosterone enanthate
- Keywords
- primary hypogonadism, secondary hypogonadism
- Medical subject headings
- Eunuchism, Hypogonadism
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Testosterone enanthateCombination product
Also called XYOSTED Injection
XYOSTED 25 mg / 0.5 mL; XYOSTED 50 mg / 0.5 mL; XYOSTED 75 mg / 0.5 mL; XYOSTED 100 mg / 0.5 mL
| Study group | Role | What they receive |
|---|---|---|
| Participants | Experimental | XYOSTED Injection (Testosterone enanthate) 25 mg / 0.5 mL, 50 mg / 0.5 mL, 75 mg / 0.5 mL, 100 mg / 0.5 mL Receives: Combination Product: Testosterone enanthate |
What is being measured
The primary outcome is the main question the study is designed to answer.
Increase in testosterone, as evaluated using PK parameters
Measured: From Enrollment through End of Study Assessments at Week 53
Secondary outcomes (7)
Percentage of participants demonstrating either progression through Tanner Stages of puberty or attainment of Tanner Stage 5 by the end of the study
Evaluated through clinical//physical examination
Measured: End of Study Assessment at Week 53
• Percentage of patients that had an increase in stretched penile length
Evaluated through clinical//physical examination
Measured: End of Study Assessment at Week 53
Change from Screening or Baseline in DEXA bone density for total body less head (TBLH) and PA spine
Evaluated through DEXA scan using age-appropriate software
Measured: End of Study Assessment at Week 53
Change from Screening or Baseline in body composition by DEXA scan
Evaluated through DEXA scan using age-appropriate software
Measured: End of Study Assessment at Week 53
Change from Screening or Baseline in bone age as determined by X-ray
Evaluated through X-ray using central readers
Measured: End of Study Assessment at Week 53
Change from Screening or Baseline in BMI-for-age percentile
Evaluated through clinical//physical examination
Measured: End of Study Assessment at Week 53
• Change from Screening or Baseline in Height Velocity (HV)
Evaluated through clinical//physical examination
Measured: End of Study Assessment at Week 53
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted14 Nov 2024
- Study start7 Mar 2025
- Primary completionMar 2028 (estimated)
- Study completionMar 2030 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Hypogonadism, MaleStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 3
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 100 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Halozyme Therapeutics
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06689085
- Sponsor's protocol ID
- ATRS QST-19-007
- Status last verified
- Nov 2026
- First submitted
- 6 Nov 2024
- Last updated
- 6 Nov 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- Yes
Study at a glance
From the registry record, last updated by the sponsor on 6 Nov 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Open-Label, Multiple-Dose, 52-Week Study + 24-Month Long-Term Safety Extension to Evaluate the Safety, PK, & Efficacy of XYOSTED® for Testosterone Replacement in Male Adolescents With Deficiency or Absence of Endogenous Testosterone Due to Primary or Secondary Hypogonadism
- ClinicalTrials.gov ID
- NCT06689085
- Acronym / sponsor ID
- ATRS QST-19-007
- Conditions
- Hypogonadism, Male
- Keywords
- primary hypogonadism, secondary hypogonadism
- Phase
- Phase 3
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 100 participants (estimated)
- Lead sponsor
- Halozyme TherapeuticsIndustry (pharma, biotech, devices)
- Study start
- 7 Mar 2025 (actual)
- Primary completion
- Mar 2028 (estimated)
- Study completion
- Mar 2030 (estimated)
- First posted
- 14 Nov 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This is a 52-week open label single arm study + 24-Month long-term safety extension to investigate the effects of XYOSTED, as testosterone replacement therapy, on adolescent males with either primary or secondary hypogonadism.
The study aims to determine the effectiveness of XYOSTED measured by continuation or induction of puberty in addition to XYOSTED dosage, safety and testosterone levels.
Detailed description
This is a Phase 3/4, open-label, multicenter study in approximately 100 males 12 to < 18 years of age with primary or secondary hypogonadism (congenital or acquired). Each participant will be screened for eligibility within 28 days before receiving his first dose of study drug on Day 1. During the Screening period, each participant will have a full clinical examination with pubertal staging, including 2 separate serum total testosterone (TT) measurements obtained in the early morning, where the average (Cavg) will be considered baseline value. Each participant will be categorized as having primary or secondary hypogonadism prior to dosing on Day 1.
Participants meeting all eligibility criteria will be assigned to a starting dose of XYOSTED based on their weight and Targeted Tanner Stage on Day 1. The Targeted Tanner Stage will be determined during Screening by an experienced pediatric endocrinologist.
Participants will have dose adjustments during the study to achieve their Targeted Tanner Stage. Dose adjustments will be based on reviewing the TT concentration between doses (Cmid) by measuring serum TT 14 days after the administration of XYOSTED for participants receiving the Q4W schedule, 7 days after the administration of XYOSTED for participants who are on the Q2W schedule, and 4 days after administration of XYOSTED for participants on the Q1W schedule. Participants will be evaluated for further dose adjustments approximately every 3 months to achieve the desired targeted TT level.
Following the 52-week primary study, participants may join a 24-month long-term safety extension study to continue the evaluation of XYOSTED in this population. Participants will return to the clinic at 6-month intervals for evaluation for clinical evaluations, and laboratory and pharmacokinetic assessments.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Participants | Experimental | Combination Product: Testosterone enanthateXYOSTED Injection (Testosterone enanthate) 25 mg / 0.5 mL, 50 mg / 0.5 mL, 75 mg / 0.5 mL, 100 mg / 0.5 mL |
Who may qualify
- Ages
- 12 to 17 years
- Sex
- Male only
- Healthy volunteers
- Not accepted
- Age groups
- Child
Key inclusion criteria (11 listed)
- Diagnosed with a deficiency or absence of endogenous testosterone due to primary or secondary hypogonadism of a known etiology. Children with combined hormone deficiencies are permitted to enroll (but the child must already be receiving treatment for concomitant hormonal deficiencies)
- Participants receiving prior testosterone treatment must be receiving a stable dose for at least 12 weeks prior to Screening. Treatment naive participants are permitted to enroll.
- Have parent(s) or a legal guardian who will voluntarily provide written informed consent for the child to participate in the study
- Willing to provide assent for participation in the study
- Be a male 12 to < 18 years of age at the time of consent/assent
Key exclusion criteria (24 listed)
- Has abnormal thyroid function tests at Screening. May supplement per usual clinical practice and rescreen up to two times.
- Has suspected or known constitutional growth delay in growth and puberty (CDGP)
- Has evidence of possible nutritional or gastrointestinal disorder that may impact growth (e.g., abrupt weight loss within the 3 months prior to Screening, unmanaged celiac disease, inflammatory bowel disease)
- Has a known allergy or hypersensitivity to XYOSTED, or to any of its ingredients (testosterone enanthate and sesame oil)
- Participants receiving prior treatment with testosterone who are not on a stable dose for at least 12 weeks prior to Screening.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Testosterone enanthateAlso: XYOSTED InjectionXYOSTED 25 mg / 0.5 mL; XYOSTED 50 mg / 0.5 mL; XYOSTED 75 mg / 0.5 mL; XYOSTED 100 mg / 0.5 mL | Combination product | Participants |
Primary outcome
Increase in testosterone, as evaluated using PK parameters
Time frame: From Enrollment through End of Study Assessments at Week 53
7 secondary outcomes
Percentage of participants demonstrating either progression through Tanner Stages of puberty or attainment of Tanner Stage 5 by the end of the study
Time frame: End of Study Assessment at Week 53
• Percentage of patients that had an increase in stretched penile length
Time frame: End of Study Assessment at Week 53
Change from Screening or Baseline in DEXA bone density for total body less head (TBLH) and PA spine
Time frame: End of Study Assessment at Week 53
Change from Screening or Baseline in body composition by DEXA scan
Time frame: End of Study Assessment at Week 53
Change from Screening or Baseline in bone age as determined by X-ray
Time frame: End of Study Assessment at Week 53
Change from Screening or Baseline in BMI-for-age percentile
Time frame: End of Study Assessment at Week 53
• Change from Screening or Baseline in Height Velocity (HV)
Time frame: End of Study Assessment at Week 53
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 6 Nov 2026.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
22 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 3 study testing Testosterone enanthate in people with Hypogonadism, Male, run by Halozyme Therapeutics at 22 sites in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 11 inclusion and 24 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 6 Nov 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 22 sites in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Director Clinical Operations, MPH, CPM (609-331-1670, jbitsura@halozyme.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Increase in testosterone, as evaluated using PK parameters (time frame: From Enrollment through End of Study Assessments at Week 53). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 6 Nov 2026; AzTrials last refreshed its copy on 7 Nov 2026.